How calorie-focused thinking about obesity and related diseases may mislead and harm public health. An alternative

Abstract

Prevailing thinking about obesity and related diseases holds that quantifying calories should be a principal concern and target for intervention. Part of this thinking is that consumed calories -regardless of their sources -are equivalent; i.e. 'a calorie is a calorie'. The present commentary discusses various problems with the idea that 'a calorie is a calorie' and with a primarily quantitative focus on food calories. Instead, the authors argue for a greater qualitative focus on the sources of calories consumed (i.e. a greater focus on types of foods) and on the metabolic changes that result from consuming foods of different types. In particular, the authors consider how calorie-focused thinking is inherently biased against high-fat foods, many of which may be protective against obesity and related diseases, and supportive of starchy and sugary replacements, which are likely detrimental. Shifting the focus to qualitative food distinctions, a central argument of the paper is that obesity and related diseases are problems due largely to food-induced physiology (e.g. neurohormonal pathways) not addressable through arithmetic dieting (i.e. calorie counting). The paper considers potential harms of public health initiatives framed around calorie balance sheetstargeting 'calories in' and/or 'calories out' -that reinforce messages of overeating and inactivity as underlying causes, rather than intermediate effects, of obesity. Finally, the paper concludes that public health should work primarily to support the consumption of whole foods that help protect against obesity-promoting energy imbalance and metabolic dysfunction and not continue to promote caloriedirected messages that may create and blame victims and possibly exacerbate epidemics of obesity and related diseases. KeywordsObesity Calories Carbohydrates Public health Chronic diseaseWith worldwide concerns about obesity and diseases related to it (e.g. diabetes and CVD), there is substantial interest in shifting populations to healthier weights and better health. More precisely, there is interest in reducing body fat since fat -particularly visceral or abdominal fat -may matter more than weight when it comes to health (1)(2)(3) . Nevertheless, much of the evidence regarding obesity and related diseases focuses on body weight, rather than body fat. In reviewing such evidence, therefore, the present paper will therefore also often use the imprecise term 'weight' as opposed to 'fat', pointing out when such imprecision might mislead thinking.One way such imprecision might mislead thinking is in supporting the notions that (i) 'a calorie is a calorie' † and (ii) intervening on calories is the best way to address obesity (i.e. the quantitative problem of excess pounds or kilograms on a scale as opposed to the qualitative problem † 'Calorie' -or more correctly kilocalorie (kcal), for which the word often imprecisely substitutes -is the main unit of energy used to discuss food and obesity-related issues in the USA. It is also the word used in common expressions l...

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